Abstract:
BACKGROUND AND PURPOSE:Animal studies have shown that MR diffusion imaging can outline acute ischemic regions before irreversible damage (infarction) occurs. To study evolution of ischemic lesions in humans, it is therefore important to quantify absolute diffusion constants (D values), but quantitation has not been reproducible among different clinics. These problems are explained, and a method for reproducible quantitation is suggested. METHODS:Diffusion-weighted and absolute diffusion images were acquired, and the absolute apparent diffusion constants in three orthogonal spatial directions (Dxx, Dyy, and Dzz) were measured. These were combined to calculate images of the orientation-independent apparent diffusion parameter Dav = 1/3 Trace[D] = 1/3(Dxx + Dyy + Dzz). Values of the individual diffusion constants and Dav were evaluated in 6 patients and 6 normal volunteers. RESULTS:Patient data show that comparison of diffusion constants between contralateral and ipsilateral hemispheres after ischemia may give results varying by more than 100% depending on orientation. Findings in normal-appearing regions containing a mixture of gray and white matter in patients (n = 5) and in normal volunteers (n = 6) show that Dav = (0.92+/-0.11) x 10(-3) mm2/s, with a small intersubject variation, whereas Dxx, Dyy, and Dzz vary strongly. Hemispheric ratios (ipsilateral/contralateral [I/C]) in these subjects were (I/C)Dav = 1.00+/-0.05, (I/C)Dxx = 1.02+/-0.15, (I/C)Dyy = 1.07+/-0.24, and (I/C)Dzz = 0.96+/-0.28. The individual subjects in this group all had an (I/C)Dav within 10% of unity, while the other three ratios showed intersubject variations as large as 100%. CONCLUSIONS:(I/C)Dav ratios are a reliable means to quantitate changes in absolute diffusion constants for the study of stroke evolution independent of tissue orientation, gradient orientation, and diffusion time. The use of these ratios will enable reproducible intersubject and interclinic quantitation.
journal_name
Strokejournal_title
Strokeauthors
Uluğ AM,Beauchamp N Jr,Bryan RN,van Zijl PCdoi
10.1161/01.str.28.3.483subject
Has Abstractpub_date
1997-03-01 00:00:00pages
483-90issue
3eissn
0039-2499issn
1524-4628journal_volume
28pub_type
杂志文章相关文献
STROKE文献大全abstract:BACKGROUND AND PURPOSE:Priorities in the care of stroke patients are often intuitive. An open and translucent priority-setting procedure would benefit patients, professionals, and decision-makers. Prioritization is an innovative part of the new Swedish national stroke guidelines. METHODS:Working groups identified diag...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/STROKEAHA.106.481457
更新日期:2007-07-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Many studies have reported frequent cognitive deficits associated with subarachnoid hemorrhage (SAH) and aneurysm repair. One study found more severe cognitive deficits after clipping than coiling of aneurysms, raising the possibility that deficits are due to surgery instead of SAH itself. This p...
journal_title:Stroke
pub_type: 临床试验,杂志文章
doi:10.1161/01.STR.0000087787.38080.B8
更新日期:2003-09-01 00:00:00
abstract:BACKGROUND AND PURPOSE:The pivotal National Institute of Neurological Disorders and Stroke recombinant tissue plasminogen activator trials excluded patients with ischemic stroke with specific minor presentations or rapidly improving symptoms. The recombinant tissue plasminogen activator product label notes that its use...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/STROKEAHA.110.593632
更新日期:2010-11-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Inflammatory cytokines are involved in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage (SAH). This study was conducted to examine the role of p38 mitogen-activated protein kinase (MAPK) in the development of vasospasm and cytokine production. METHODS:We measured the expressi...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/01.STR.0000127425.47266.20
更新日期:2004-06-01 00:00:00
abstract:BACKGROUND AND PURPOSE:The significance of structural changes associated with cerebral small-vessel disease (SVD), including white matter lesions (WML), lacunes, and brain atrophy, to outcome from acute intracerebral hemorrhage is uncertain. We determined associations of computed tomographic radiological manifestations...
journal_title:Stroke
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1161/STROKEAHA.115.012147
更新日期:2016-03-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Specialized management of patients with stroke is not available in all hospitals. We evaluated whether prehospital management in the Stroke Emergency Mobile (STEMO) improves the triage of patients with stroke. METHODS:STEMO is an ambulance staffed with a specialized stroke team and equipped with...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/STROKEAHA.114.008159
更新日期:2015-03-01 00:00:00
abstract::Reduction in cerebral blood flow (CBF) following global ischemia has been implicated as a pathogenetic mechanism in progressive brain damage seen after restoration of effective cardiac action and cerebral perfusion pressure. There are serious limitations to many of the techniques for measuring regional cerebral blood ...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/01.str.12.1.66
更新日期:1981-01-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Data from recent multicenter carotid endarterectomy trials have questioned the validity and reliability of Doppler ultrasound in the assessment of carotid stenosis. METHODS:We prospectively analyzed 45 patients undergoing carotid angiography to compare the North American Symptomatic Carotid Enda...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/01.str.24.9.1292
更新日期:1993-09-01 00:00:00
abstract::Background and Purpose- The purpose of this study was to conduct a meta-analysis of CVOTs (cardiovascular outcome trials) to evaluate the effect of glucagon-like peptide-1 receptor agonists therapy in reducing the risk of stroke in patients with type 2 diabetes mellitus. Methods- PubMed and other electronic sources we...
journal_title:Stroke
pub_type: 临床试验,杂志文章
doi:10.1161/STROKEAHA.119.027557
更新日期:2020-02-01 00:00:00
abstract:BACKGROUND AND PURPOSE:The goal of the Stroke Treatment Academic Industry Roundtable (STAIR) meetings is to advance the development of acute and restorative stroke therapies. Summary of Review- At the STAIR VII recommendations for strategies to maximize the use of intravenous thrombolytics through targeting public educ...
journal_title:Stroke
pub_type: 杂志文章,实务指引
doi:10.1161/STROKEAHA.111.618850
更新日期:2011-09-01 00:00:00
abstract:BACKGROUND AND PURPOSE:We know that significant cardiac involvement can occur in patients with acute intracranial hemorrhage, particularly in those with subarachnoid hemorrhage. These patients may present with electrocardiographic abnormalities that were previously thought to be benign. However, many die of cardiovascu...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/01.str.27.4.737
更新日期:1996-04-01 00:00:00
abstract:BACKGROUND AND PURPOSE:We have shown that acute treatment with candesartan in an experimental model of stroke resulted in vascular protection and improved outcomes at 24 hours poststroke, but the mechanisms are unknown. We now examine effects of candesartan on proangiogenic factors and 7-day outcomes using the same tre...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/STROKEAHA.108.537225
更新日期:2009-05-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Oxidative damage of mitochondrial DNA (mtDNA) in the ischemic brain is expected after ischemia/reperfusion injury. A recent study demonstrated limited patterns of mtDNA deletion in the brain after ischemia/reperfusion. We studied the ischemia/reperfusion-induced global changes of mtDNA integrity ...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/hs1001.097099
更新日期:2001-10-01 00:00:00
abstract:BACKGROUND AND PURPOSE:The Intravenous Nimodipine West European Stroke Trial (INWEST) found a correlation between nimodipine-induced reduction in blood pressure (BP) and an unfavorable outcome in acute stroke. We sought to confirm this correlation with and without adjustment for prognostic variables and to investigate ...
journal_title:Stroke
pub_type: 临床试验,杂志文章
doi:10.1161/01.str.31.6.1250
更新日期:2000-06-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Physiologically, it appears plausible for physical activity to decrease stroke risk; however, epidemiological studies have produced mixed findings. Furthermore, few studies have examined specific kinds and intensities of activities. The purpose of this study was to examine the association between...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/01.str.29.10.2049
更新日期:1998-10-01 00:00:00
abstract:BACKGROUND AND PURPOSE:In children having suffered from neonatal arterial ischemic stroke, the relationship between contralesional hand performance and structural changes in brain areas remote from the infarct site was examined. METHODS:Using voxel-based morphometry, we correlated contralesional gross manual dexterity...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/STROKEAHA.116.013545
更新日期:2016-06-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Many foods have been suggested to influence the risk of stroke. However, no previous studies have examined the relationship between overall dietary patterns and risk of stroke. METHODS:Using dietary information collected in 1984 from 71,768 women aged 38 to 63 years without a history of cardiova...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/01.STR.0000135762.89154.92
更新日期:2004-09-01 00:00:00
abstract::There have been numerous failures in the field of acute stroke therapy over many years, but the first large clinical trial showing preliminary indications of efficacy and safety of a neuroprotective drug, NXY-059, has now been fully reported. If confirmed, it will mean that a second therapy for acute stroke has been i...
journal_title:Stroke
pub_type: 杂志文章,评审
doi:10.1161/01.STR.0000252090.44428.82
更新日期:2007-02-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Incidental magnetic resonance diffusion-weighted imaging (DWI)-positive lesions, considered to represent small acute infarcts, have been detected in patients with cerebral small vessel diseases or cognitive impairment, but the prevalence in the community population is unknown. METHODS:DWI sequen...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/STROKEAHA.114.005782
更新日期:2014-07-01 00:00:00
abstract:BACKGROUND AND PURPOSE:In 2008, the Ministry of Health and Welfare of South Korea initiated the Regional Comprehensive Stroke Center (CSC) program to decrease the incidence and mortality of stroke nationwide. We evaluated the performance of acute ischemic stroke management after the Regional CSC program was introduced....
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/STROKEAHA.114.006134
更新日期:2014-08-01 00:00:00
abstract:BACKGROUND AND PURPOSE:We compared among young patients with ischemic stroke the distribution of vascular risk factors among sex, age groups, and 3 distinct geographic regions in Europe. METHODS:We included patients with first-ever ischemic stroke aged 15 to 49 years from existing hospital- or population-based prospec...
journal_title:Stroke
pub_type: 杂志文章,多中心研究
doi:10.1161/STROKEAHA.112.662866
更新日期:2012-10-01 00:00:00
abstract:BACKGROUND AND PURPOSE:the association of autosomal-dominant polycystic kidney disease (ADPKD) with intracranial aneurysm (ICAN) is well known but little is known about the characteristics of ICAN in ADPKD. The purpose of this study was to investigate the prevalence and characteristics of ICAN in ADPKD. METHODS:we scr...
journal_title:Stroke
pub_type: 临床试验,杂志文章,多中心研究
doi:10.1161/STROKEAHA.110.578740
更新日期:2011-01-01 00:00:00
abstract::We determined the immediate effects of pentoxifylline on cerebral blood flow in 10 patients with cerebrovascular disease; four received 400 mg and six received 800 mg pentoxifylline orally. Regional cerebral blood flow was measured before (baseline) and 2, 4, and 6 hours after pentoxifylline administration using the x...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/01.str.20.12.1662
更新日期:1989-12-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Choroid plexus (CP) secretes a cocktail of neurotrophic factors. In the present study, CP from neonatal pigs was encapsulated within alginate microcapsules for in vitro and in vivo neuroprotective studies. METHODS:In vitro studies involved serum deprivation of rat embryonic cortical neurons and ...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/01.STR.0000138954.25825.0b
更新日期:2004-09-01 00:00:00
abstract::The European Stroke Organisation held its first European Stroke Science Workshop in Garmisch-Partenkirchen, Germany (December 15-17, 2011). Stroke experts based in Europe were invited to present and discuss their current research. The scope of the workshop was to review the most recent findings of selected topics in s...
journal_title:Stroke
pub_type:
doi:10.1161/STROKEAHA.112.655373
更新日期:2012-09-01 00:00:00
abstract::The effect of respiration on the cerebrovascular response to elevated intracranial pressure (ICP) was studied in anesthetized dogs. Total and regional cerebral blood flows were measured using labelled microspheres. In spontaneously breathing dogs total and regional cerebral blood flows increased when cerebral perfusio...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/01.str.8.2.243
更新日期:1977-03-01 00:00:00
abstract:BACKGROUND AND PURPOSE:The effect of statins on progression of carotid intima-media complex thickness (IMT) has been shown exclusively in nonstroke Western patients. This study aimed to determine the effect of low-dose pravastatin on carotid IMT in Japanese patients with noncardioembolic ischemic stroke. METHODS:This ...
journal_title:Stroke
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1161/STROKEAHA.117.018387
更新日期:2018-01-01 00:00:00
abstract::Regional cerebral blood flow (CBF) was measured (intra-arterial injections of 133Xe) and electroencephalograms (EEG) were recorded periodically before, for two hours during, and for one and one-fourth hours after middle cerebral artery (MCA) occlusion in 20 squirrel monkeys (Saimiri sciureus). A CBF-Paco2 response cur...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/01.str.6.2.121
更新日期:1975-03-01 00:00:00
abstract:BACKGROUND AND PURPOSE:There have been relatively few community-based studies of long-term prognosis after acute stroke. This study aimed to provide precise estimates of the absolute and relative risks of dying in an unselected cohort of patients with a first-ever stroke. METHODS:Six hundred seventy-five patients were...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/01.str.24.6.796
更新日期:1993-06-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Severe cerebral edema is associated with poor outcome in patients with acute stroke. Experimental studies suggest that astrocytic endothelin-1 (ET-1) has deleterious effects on water homeostasis, cerebral edema, and blood brain barrier (BBB) integrity, which contribute to more severe ischemic bra...
journal_title:Stroke
pub_type: 杂志文章
doi:10.1161/STROKEAHA.107.495044
更新日期:2008-07-01 00:00:00